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Pigging Tips

The following tips are designed to assist in decision making when considering installation of an HPS Pigging System. These are guidelines that will ensure a robust system is installed.

Choosing a system: Where is my Return of Investment (ROI)

HPS understands that for any capital purchase there needs to be a good return of investment. It is therefore important to understand all areas that this can be achieved when considering installing HPS Pigging Systems or other HPS technologies.

Although there are some that you can immediately identify, sometimes there are some not so obvious savings that can be added to your investment calculations.

Pigging will reduce product waste that is normally washed to drain, a waste collection area, a waste treatment area or even a recovery tank. The waste is not just the volume of product lost, it also includes the fluid used to evacuate this product and the power resources to make this happen. The cost of waste treatment may require chemical, power or human resources.
Pigging will increase product yield near to the amount of product that is normally wasted. This depends on any restrictions of Pig Launcher & Pig Receiver locations. This is good product and can packed and sold.
Pigging can reduce cleaning times which in turn reduce power and human resources required for this function.
Pigging can reduce batch changeover times, thus increasing production time available and reducing power & human resources required per batch.
Pigging water or cleaning fluid residue after a washout or CIP will prevent product dilution at the start of a new product batch. Consider how much product you currently need to run off before the product is in spec. for filling or storage.
Pigging may allow you to change over batches without a washout if the products do not have a significant colour, fragrance, flavour or ingriedient change allowing you to save cleaning fluid, power & human resources whilst making available more production time.
Do you have foaming, aeration or oxygen pick up problems at start up of a new batch of product? An HPS double Pig system can help prevent this, allowing product to be in spec. as it reaches the filler.
Pigging can maintain your pipe integrity by preventing material build up on pipe walls. This could prevent significant downtime to manually remove the material build up ad the human resources required to carry out this function.
Liquid manufacturing companies accross the world now see Carbon Footprint Reduction as a marketing tool. Pigging will significantly reduce companies direct and indirect Carbon Footprints. Directly consider the power resources that can be saved by reducing cleaning times and associated waste. Indirectly consider the reduction tankers or trucks required for removal of waste or delivery of waste treatment chemicals, which will reduce road degredation, exhaust emissions and traffic congestion. Also consider the containers that waste treatment chemicals are delivered it, a factory has to make these and they have to be re-collected or disposed of.

Choosing a system: New Installation

This is the best time to review HPS technologies as some products can rationalise piping arrangements and equipment as well as the opportunity to install the best possible infrastructure for Pigging.

The HPS Piggable Rotomatrix System allows the operator to manually make multi-source, multi destination product transfer connections, which enable excellent plant flexibility. This product removes the need for Flow Plates / Flow Panels / Bend Panels / Flow Verters which do not give the plant flexibility required without complexed arrangements of connections and varying sizes of bend connections. The maximum range of the Rotomatrix is 9 rotating Arms to 20 fixed connections.
The HPS Piggable Automatrix System allows automatic selection of multi-source, multi destination product transfer connections, which enable excellent plant flexibility. This system offers the same benefits as the HPS Rotomatrix but can expand to meet as many sources & destinations as required.
For new installations it is possible to specify HPS recommendations detailed later in this document such as orbital welding for the pipe and robust pipe supports.

Choosing a system: Existing Installation

Where possible HPS try to retrofit systems into existing pipelines and make any neccessary recommendations neccessary to ensure effective operation.

Consider the recommendations detailed in the infrastructure section of this document.

Choosing a system: Type

HPS will design a system that meets with your requirements, but it is worth considering the options that are available prior to requesting a quotation.

Single Pig System - Transferring and Pigging product from a single source to a single destination
Double Pig System - One Pig is located at the pump outlet and at start up is pushed by product to the destination preventing foaming, aeration or oxygen pickup. The second Pig is used as normal to recover the product that remains at the completion of a batch.
Tank Select System (In)- Transferring and Pigging product from a single source to multiple tanks or fillers.
Tank Select System (Out) - Transfering and Pigging product from any one of multiple tanks to a single Filler.
Product Separation System - Using a Pig to separate one product from the next OR to separate expensive cleaning fluids in longer lines
Multi-Source, Multi Destination System - Rotomatrix (see Choosing a system: New Installation)
Multi-Source, Multi Destination System - Automatrix (see Choosing a system: New Installation)

Infrastructure

The most important component of a any Pigging System is the pipeline

There should be no dents or damage along the length of the pipe to be pigged.
Welds must be clean and have minimal intrusion to internal bore of the pipe.
Verify there is no internal intrusion of gaskets from pipe couplings. Tri-clamps and standard flanges are connections that can have this effect. Tri-clamps are viewed as one of the most sanitary / hygienic connections, however this is only true if they are installed correctly. If the clamps are over-tightened the gaskets will intrude internally into the pipe causing a restriction for the Pig and potentially a contamination risk. To help avoid this intrusion HPS recommend using either teflon or teflon envelope gaskets, which are more resistant to intrusion. Alternatively consideration could be given to the use of a different type of connection such as the I-Line fitting in the USA, RJT - CIP Modified in Australia, SMS, IDF or DIN in Europe. For less sanitary applications consideration could be given to the use of 'spigot' flanges ie. flanges that key together, preventing misalignment.
Consider using anti-vibration cushion sleeve pipe support clamps be instead of metal on metal clamps. Ths will help prevent progressive damage to the pigged pipe.
HPS recommend using rigid supports such as 'L' frame for the pigged pipe instead of rod hangers. This will prevent possible movement of the pipe whilst the Pig is being used.
Consider the use of pipe for compressed air, Co2 or Nitrogen services used for Pig propellant. Flexible air lines can get distorted and prevent air flow.
Consider availability of compressed gas services used for Pig propellant. The MINIMUM volume will be the volume of the Pigged pipe.

Mechanical Installation

In most cases HPS will consult and work with your preferred local contractor, however this service can be provided if required.

Use a good process welding company and inform them that this will be a Pigged pipeline.
Orbital welding is preferred where possible. Where it is not possible, consider installation of a coupling that will allow inspection or polishing of the weld.
The Pigging equipment should be installed where there is access for maintenance or Pig inspection.
Vent / Drain lines from Pig Launchers should be kept to a minimum length.
NEVER connect Vent / Drain lines together from other Pig Launchers. This could cause operational and contamination issues.
NEVER connect the Vent / Drain Lines directly to the main drain. This could cause operational and contamination issues. Leave a gap between the Vent / Drain outlet and the main drain. Use a funnel to prevent spray when the line is de-pressurising.

Electrical Installation

In most cases HPS will consult and work with your preferred local contractor, however this sevice can be provided if required.

HPS can provide networked field devices if required
Consider the use of remote I/O
HPS can provide systems for Hazardous Areas

PLC / HMI Control Panels

In many cases HPS systems are integrated into existing client PLC / HMI Control Panels, however HPS can provide control panels if required.

HPS are most familiar with Allen Bradley, Siemens & Mitsibushi control gear, however we can accomodate most manufacturers.
Consider where the operator of the system/s will be when the system is required for use. Perhaps the control panel should be remote from the Operator HMI.

PLC / HMI Programming

HPS can provide both PLC & HMI Programming for the Pigging Systems OR provide a Functional Design Specification (FDS) for client selected programmers.

HPS prefer to construct and integrate the PLC / HMI Programming as we have proven library code for many elements of system control and it also allows the company to better support the systems in the future.
If it is still the clients preference to use local programmers then HPS would provide a detailed Functional Design Specification. During commissioning this document would be used to validate the system. However it should be considered that HPS will not be able to software support of the system.

Commissioning / Training

It is compulsory for HPS to commission any first system for our clients. This ensures the guarantee for the system and will allow the users to be trained properly in the functionality of the system and how to deal with any issues that may occur. For further future systems we can evaluate if HPS representation is required.

Preventive Maintenance

Other than standard maintenance for soft seal/gasket replacement there are only a few elements of the Pigging System that need be included in preventive maintenance.

Pigs - HPS offer a guarantee of 90,000ft (30,000m) for Pigs recovering products at ambient or near ambient temperatures. In most cases our experience shows that the Pigs are used for much longer distances depending on the environment they are operating in. However, it should be noted that if the Pigs are used until they don't function anymore it is possible fluid or gases could bypass the pig during operation. The Pig could also get held up in the line causing down time. Consider periodic inspection of the Pig to ensure it is in good condition.
Hot products may reduce the life of the Pig. This Pig condition should be monitored over the first few weeks to gauge the condition. Consider the use of 3D bends in hot applications to enhance the life of the Pig.
If filters exist on the propellant gas lines for the Pig, then these should be replaced as a minimum annually or as required.
For Sanitary / Hygienic Systems using the HPS CIP Ball Valves with Inflatable Seal Technology seal replacement must be carried out at 6 month intervals. For more stressful environments HPS will recommend an alternative change out period.
For systems using traditional teflon seal technology Ball Valves HPS recommend annual replacement.
HPS recommend that spare parts are carried by the client to ensure the systems can be maintained or repaired as quickly as possible.

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Hygienic Pigging Systems Ltd, 5 Edison Village, Nottingham Science and Technology Park, University Boulevard, Nottingham, Nottinghamshire, NG7 2RF
Company Number 02974969